Comparison between Flow Cytometry and Traditional Culture Methods for Efficacy Assessment of Six Disinfectant Agents against Nosocomial Bacterial Species.

The present study was undertaken to compare the use of flow cytometry (FCM) and traditional culture methods for efficacy assessment of six disinfectants used in Quebec hospitals including: two quaternary ammonium-based, two activated hydrogen peroxide-based, one phenol-based, and one sodium hypochlorite-based. Four nosocomial bacterial species, , and Vancomycin-resistant , were exposed to minimum lethal concentrations (MLCs) and sublethal concentrations (1/2 MLCs) of disinfectants under study. The results showed a strong correlation between the two techniques for the presence of dead and live cell populations, as well as, evidence of injured populations with the FCM.

Modulation of morphogenesis in Candida albicans by various small molecules.

The pathogenic yeast Candida albicans, a member of the mucosal microbiota, is responsible for a large spectrum of infections, ranging from benign thrush and vulvovaginitis in both healthy and immunocompromised individuals to severe, life-threatening infections in immunocompromised patients. A striking feature of C. albicans is its ability to grow as budding yeast and as filamentous forms, including hyphae and pseudohyphae.

Conjugated linoleic acid inhibits hyphal growth in Candida albicans by modulating Ras1p cellular levels and downregulating TEC1 expression.

The polymorphic yeast Candida albicans exists in yeast and filamentous forms. Given that the morphogenetic switch coincides with the expression of many virulence factors, the yeast-to-hypha transition constitutes an attractive target for the development of new antifungal agents. Since an untapped therapeutic potential resides in small molecules that hinder C.

Temperature and length-dependent modulation of the MH class II beta gene expression in brook charr (Salvelinus fontinalis) by a cis-acting minisatellite.

It is widely recognized that the variation in gene regulation is an important factor from which evolutionary changes in diverse aspects of phenotype can be observed in all organisms. Distinctive elements with functional roles on gene regulation have been identified within the non-coding part of the genome, including repeated elements. Major histocompatibility complex (MHC) genes have been the subject of an abundant literature which made them unique candidates for studies of adaptation in natural populations.

Contribution of the C-terminal region within the catalytic core domain of HIV-1 integrase to yeast lethality, chromatin binding and viral replication.

Background: HIV-1 integrase (IN) is a key viral enzymatic molecule required for the integration of the viral cDNA into the genome. Additionally, HIV-1 IN has been shown to play important roles in several other steps during the viral life cycle, including reverse transcription, nuclear import and chromatin targeting. Interestingly, previous studies have demonstrated that the expression of HIV-1 IN induces the lethal phenotype in some strains of Saccharomyces cerevisiae.

Identification of MHC class IIbeta resistance/susceptibility alleles to Aeromonas salmonicida in brook charr (Salvelinus fontinalis).

Pathogen-driven selection is believed to be important in the evolution and maintenance of the polymorphism of the major histocompatibility complex (MHC) genes but have been tested for very few vertebrates. In this study, we first investigate by SSCP (single strand conformational polymorphism) the diversity found at the MHC class IIbeta gene in a population of brook charr (Salvelinus fontinalis) from the Rupert River (Québec, Canada). Secondly, to explore the survival performances conferred by specific alleles and genotypes, individuals from 23 half- and full-sibling families were infected with Aeromonas salmonicida, the causative agent of furonculosis.

Whey-derived free fatty acids suppress the germination of Candida albicans in vitro.

Bovine whey from the cheese-making industry contains several bioactive factors that promote health and prevent disease. Although many efforts have been made over the years to show that immunoglobulins, lactoperoxidase, lactoferrin, lysosyme and small peptides present in whey have antimicrobial activities against several pathogenic microorganisms, such activities have not been investigated so far for the lipid fraction of whey. Here, we have used an in vitro assay-based fractionation procedure to show that free fatty acids derived from whey cream specifically inhibit the germination of Candida albicans, a morphologic change associated with pathogenicity.

The nuclear GTPase Gsp1p can affect proper telomeric function through the Sir4 protein in Saccharomyces cerevisiae.

The small Ras-like GTPase Ran/Gsp1p is a highly conserved nuclear protein required for the nucleocytoplasmic trafficking of macromolecules. Recent findings suggest that the Ran/Gsp1p pathway may have additional roles in several aspects of nuclear structure and function, including spindle assembly, nuclear envelope formation, nuclear pore complex assembly and RNA processing. Here, we provide evidence that Gsp1p can regulate telomeric function in Saccharomyces cerevisiae.

Genetic selection of peptide inhibitors of human immunodeficiency virus type 1 Vpr.

Human immunodeficiency virus 1 (HIV-1) encodes a gene product, Vpr, that facilitates the nuclear uptake of the viral pre-integration complex in non-dividing cells and causes infected cells to arrest in the G(2) phase of the cell cycle. Vpr was also shown to cause mitochondrial dysfunction in human cells and budding yeasts, an effect that was proposed to lead to growth arrest and cell killing in budding yeasts and apoptosis in human cells. In this study, we used a genetic selection in Saccharomyces cerevisiae to identify hexameric peptides that suppress the growth arrest phenotype mediated by Vpr.

Effect of the echinocandin caspofungin on expression of Candida albicans secretory aspartyl proteinases and phospholipase in vitro.

Although the echinocandin caspofungin primarily inhibits the synthesis of cell wall 1,3-beta-D-glucan, its fungicidal activity could also potentially perturb the expression of virulence factors involved in the ability of Candida albicans to cause infection. Expression of the C. albicans secretory aspartyl proteinase (SAP) and phospholipase B (PLB) virulence genes was determined by reverse transcription-PCR after the addition of caspofungin to cells grown for 15 h in Sabouraud dextrose broth.

Evidence for differential expression of candida albicans virulence genes during oral infection in intact and human immunodeficiency virus type 1-transgenic mice.

To comprehensively assess the in vivo expression of Candida albicans hydrolytic enzyme genes during oropharyngeal candidiasis (OPC), a controlled sequential analysis of the temporal expression of individual members of the SAP (secretory aspartyl proteinase) gene family and PLB1 (phospholipase B) in a murine model of OPC was conducted. Acute infections in intact C3H and DBA/2 mice were terminated by clearance of C. albicans within 7 days after oral inoculation, but transgenic (Tg) mice expressing human immunodeficiency virus type 1 were persistently colonized until a final outgrowth before death.

Overexpression of Candida albicans secretory aspartyl proteinase 2 and its expression in Saccharomyces cerevisiae do not augment virulence in mice.

To elucidate the implications of secreted aspartyl proteinase (Sap)2p in the pathogenesis of Candida infections, the SAP2 gene was expressed in Saccharomyces cerevisiae and overexpressed in Candida albicans. The coding region of SAP2, including its signal sequence and propeptide, was amplified by PCR and cloned downstream of the S. cerevisiae or C.